Lumbar facet joint denervation targeting the medial branch in the sub-mammillary fossa: An anatomical optimization study

Introduction

Recent anatomical studies have identified the sub-mammillary fossa as a potential target site to extend the length and more reliably capture the medial branch during lumbar facet joint denervation. Although a clinical case series was published describing positive outcomes targeting the sub-mammillary fossa, the ideal location for radiofrequency cannula placement has not been assessed. Further anatomical investigation of this novel technique is warranted to refine fluoroscopic landmarks for optimal placement.

Methods

Twelve cannulae were placed under fluoroscopic guidance targeting the L3, L4, & L5 medial branches in 2 embalmed cadaveric specimens. Dissection, digitization, and high-fidelity 3D modelling methodology was used to identify fluoroscopic landmarks. Lesion simulation was performed on 3D models to analyze nerve capture.

Results

In 5 of 12 placements (41.7 %), the medial branch capture rate was classified as "complete," as the simulated lesion overlapped with the medial branch trunk or all of its distal branches. In 4 of 12 placements (33.3 %), the nerve capture rate was "partial" with at least one distal branch found beyond the boundary of the simulated lesion. In the remaining 3 placements (25.0 %), the capture rate was classified as "none," as the medial branch trunk and all distal branches transited beyond the simulated lesion boundary. Refined fluoroscopic landmarks proposed were the lateral boundary of mammillary process (AP view); the mamillo-accessory notch/inferior boundary of facet joint line (oblique view); and the inferior aspect of the mammillary process (lateral view).

Conclusions

This anatomy optimization study used dissection, imaging correlation, and high-fidelity modelling to assess cannula placement for capture of the medial branch at the sub-mammillary fossa for lumbar facet joint denervation. Based on the present analysis, refined fluoroscopic landmarks were proposed for further investigation.

A retrospective single arm cohort study evaluating the efficacy of lumbar medial branch radiofrequency ablation using a multi-tined probe and perpendicular approach

Summary of background data

Lumbar medial branch radiofrequency ablation (LMBRFA) is an effective treatment for facet joint pain. LMBRFA efficacy was originally demonstrated using a parallel technique. Newly developed RFA probes (e.g., Trident) allow a perpendicular approach (P-LMBRFA), which may simplify the RFA technique and lead to superior treatment success rates. However, further investigation is necessary to determine whether these technologies are associated with improved patient outcomes.

Objectives

Evaluate the effectiveness of P-LMBRFA in patients with confirmed facet pain.

Methods

In this retrospective single-arm cohort study, electronic medical records were used to identify consecutive patients with ≥80 % dual medial branch block-confirmed pain relief who underwent first-time P-LMBRFA between 2016 and 2022. Primary outcomes were ≥50 % Numerical Rating Scale (NRS) pain improvement and the minimal clinically important difference (MCID) on the Pain Disability Quality-of-Life Questionnaire (PDQQ) at 3 months post-treatment. Secondary outcomes included the duration and mean retrospective percentage of pain relief after a successful index P-LMBRFA in individuals who reported a return of their index symptoms.

Results

174 participants (60.3 % female, 61.3 ± 14.2 years of age, BMI 29.5 ± 6.7 kg/m2) were analyzed. Success rates for ≥50 % NRS reduction and MCID on the PDQQ at 3 months were 50.6 % (95 % CI = 43.3-57.9 %) and 50.0 % (95 % CI = 42.8-57.2 %), respectively. Of the 88 successful P-LMBRFAs, 60 patients experienced a return of symptoms after 8.7 ± 3.6 months and reported a retrospective mean percentage pain relief of 81.8 % ± 15.8 %.

Discussion/conclusion

Following P-LMBRFA, approximately 50 % of patients reported improvement in pain and disability measures. Extensive, prospective research comparing long-term outcomes of P-LMBRFA and parallel LMRBFA is warranted.

True AP imaging during lumbar medial branch radiofrequency neurotomy: A technical note

Background

Optimal outcomes following lumbar medial branch radiofrequency neurotomy (LMBRFN) require close and parallel electrode placement to the targeted medial branch. True segmental fluoroscopic imaging is critical for LMBRFN performance. A true lateral imaging technique for LMBRFN has been described, and its interobserver reliability has been established. However, a similarly detailed technique for true AP imaging has yet to be proposed.

Objective

This technical note proposes a clear and concise true AP imaging technique for LMBRFN.

Technique

True AP lumbar imaging involves viewing the spinous process in the midline or midway between the pedicles and aligning cortical bone to create a sharp, superior endplate image. Maneuvering the fluoroscope can produce true AP imaging if the initial AP image is untrue. Oblique (axial plane) fluoroscopic rotation allows the spinous process to be positioned appropriately in the midline. Right versus left oblique rotation is informed by the position of the spinous process relative to the midline. Tilt (longitudinal plane) fluoroscopic rotation produces a sharp superior endplate. Cranial versus caudal tilt is informed by the pedicles' position relative to the vertebral body's upper zone.

Conclusions

When combined with true lateral imaging, the currently proposed AP imaging technique may yield reliable true segmental imaging during LMBRFN. This true AP segmental imaging process may also be applied to other lumbar spine procedures.

The effectiveness of thoracic medial branch radiofrequency neurotomy using a three-tined electrode: A single-arm, retrospective cohort study

Background

Thoracic medial branch radiofrequency neurotomy (TMBRFN) is used to treat chronic thoracic facet joint pain, but research on its technique and effectiveness is still needed. The current International Pain and Spine Intervention Society Practice Guidelines do not describe a technique for TMBRFN.

Objectives

Evaluate the effectiveness of TMBRFN in patients with thoracic facet joint pain.

Methods

Single-arm, retrospective cohort study of consecutive patients from two Canadian musculoskeletal pain management clinics who underwent first-time TMBRFN between 2016 and 2022. The primary outcome was the proportion of patients with ≥50 % reduction in numerical rating scale (NRS) pain score at 3-months post-procedure. Secondary outcomes included the proportion of patients who achieved a ≥17-point reduction on the Pain Disability Quality-Of-Life Questionnaire-Spine (PDQQ-S) at 3-months, as well as mean patient-reported percentage pain relief and duration of relief after a successful index TMBRFN in individuals who reported a return of their index symptoms.

Results

18 consecutive patients (50.0 % male; mean age 60.9 ± 15.3 years; mean BMI 30.3 ± 6.9 kg/m2) were analyzed. At 3 months post-procedure, 10 patients (55.6 % [95%CI 33.7-75.4]) reported ≥50 % NRS pain reduction and 9 (50.0 % [95%CI 29.0-71.0]) reported ≥17-point PDQQ-S reduction. Of the 10 patients with successful treatment responses, 4 had a return of symptoms after an average of 9.3 ± 2.2 months with a reported retrospective mean percentage pain relief of 70.0 ± 34.6 %.

Conclusion

Within this cohort, approximately 60 % of patients experienced improvement in pain and disability at 3 months following TMBRFN. Among patients whose index symptoms returned after successful treatment, the average reported pain relief was 70 % for close to 9 months. Larger, prospective studies with long-term outcomes are needed to better elucidate the safety and effectiveness of TMBRFN.

Evaluation of a novel nerve ablation technique to relieve lower back pain: a cadaveric feasibility pilot study

INTRODUCTION

Radiofrequency ablation is a treatment for facetogenic low back pain that targets medial branches of lumbar dorsal rami to denervate facet joints. Clinical outcomes vary; optimizing cannula placement to better capture the medial branch could improve clinical outcomes. A novel parasagittal technique was proposed from an anatomic model; this technique was proposed to optimize capture of the medial branch. The anatomic feasibility of the novel technique has not been evaluated.

OBJECTIVE

To simulate and evaluate the proposed parasagittal technique in its ability to achieve proper cannula placement and proximity of uninsulated cannula tips to the medial branches of the dorsal rami in cadaveric specimens.

METHODS

Under fluoroscopic guidance, the parasagittal technique was used to place 14 cannulae targeting the lumbar medial branches of 2 cadavers. Meticulous dissection was undertaken to assess cannula alignment and measure proximities to target nerves with a digital caliper.

RESULTS

The novel parasagittal technique was successfully performed in a cadaveric model in 12 of 14 attempts. The technique achieved close proximity of cannula tips to medial branches (0.8 ± 1.1 mm). In 2 instances, cannulae were placed unsuccessfully; in one instance, the cannula was too far anterior, and in the other, it was too far retracted.

CONCLUSION

In this cadaveric simulation study, the feasibility of performing the parasagittal technique for lumbar radiofrequency ablation was evaluated. This study suggests that the parasagittal technique is a feasible option for lumbar medial branch radiofrequency ablation.

The effectiveness of sacral lateral branch radiofrequency neurotomy for posterior sacroiliac joint complex pain in patients selected by dual sacral lateral branch blocks; A real-world cohort study

Background

Previous study of spinal neurotomy procedures indicates that stringent block selection improves outcomes. However, this pattern is not established for sacral lateral branch radiofrequency neurotomy (SLBRFN). Few SLBRFN studies have used stringent block selection criteria such as ≥80 % pain reduction following dual sacral lateral branch blocks (SLBB).

Objective

Evaluate the effectiveness of SLBRFN in patients with ≥80 % pain relief following dual SLBBs.

Methods

Retrospective single-arm cohort study of consecutive patients from two Canadian musculoskeletal and pain clinics who underwent first-time SLBRFN after report of ≥80 % pain relief following dual diagnostic SLBBs. Patients were identified by electronic medical record query between 2016 and 2022. The primary outcome was the proportion of individuals with a ≥50 % reduction in the numeric pain rating scale (NPRS) score three months after SLBRFN. Secondary outcomes included the proportion of responders achieving the minimal clinically important difference (MCID) on the pain disability quality-of-life questionnaire (PDQQ), and the duration and mean percentage of pain relief among those with recurrent symptoms after a successful SLBRFN.

Results

Of the 70 participants included, 32 (45.7 %; 95 % CI = 34.6-57.3) reported a ≥50 % reduction in NPRS, and 35 (50.0 %; 95 % CI = 38.6-61.4) achieved the MCID on the PDQQ at 3-months. Among the 17 patients who reported a return of symptoms, the mean duration of relief was 8.0 ± 3.5 months, and the mean percentage of pain relief was 77.9 % ± 16.4 %. Logistic regression models revealed that the use of multi-tined RF probes and lower patient BMI were associated with treatment success.

Discussion/conclusion

SLBRFN reduced pain and disability in approximately 50 % of patients at 3 months when selected using relatively restrictive selection criteria. Treatment success was associated with multi-tined RF probe type and lower patient BMI. Larger prospective studies assessing long-term outcomes are needed to further evaluate the impact of different selection criteria and techniques on SLBRFN effectiveness.

Glucocorticoid facet joint injection for chronic back or neck pain

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: The primary objective is to assess the benefits and harms of glucocorticoid facet joint injections in adults with chronic back or neck pain that is presumed to be facet joint-mediated. The secondary objective is to assess whether the effects differ by diagnostic method for facet joint-mediated pain.

Lumbar Facet Joint Disease: What, Why, and When?

Low back pain (LBP) affects over 60% of individuals in their lifetime and is a leading cause of disability and increased healthcare expenditure. Facet joint pain (FJP) occurs in 27% to 40% of LBP patients but is often overlooked or misdiagnosed. Additionally, there is no clear correlation between the clinical examination, radiological findings, and clinical presentation, complicating the diagnosis and treatment of FJP. This narrative review aims to provide an overview of the literature regarding facet joint pain and discusses the utility of medial branch blocks (MBBs) and intra-articular (IA) injections as diagnostic and therapeutic tools prior to radiofrequency ablation (RFA). RFA is considered the gold standard for managing FJP, employing techniques that include precise needle placement and stimulation parameters to disrupt pain signals. Promising alternatives such as cooled RFA and cryodenervation require further research on their long-term efficacy and safety. Endoscopic denervation and multifidus stimulation are emerging therapies that may benefit chronic LBP patients, but additional research is needed to establish their effectiveness. When conservative management fails, RFA provides significant and lasting relief in well-selected patients and has a favourable safety profile. The current literature does not support surgical interventions for FJP management.

Clinical pain management: Current practice and recent innovations in research

Chronic pain affects one in five adults. It is not only a major cause of disability for individual patients but also a driver of costs for entire healthcare systems. Treatment of pain remains a challenge, and the use of opioids has further led to a concurrent opioid epidemic. In this review, we discuss current standard treatment options for chronic pain, including pharmacological, behavioral, and interventional treatments. In addition, we review ongoing research in different areas that will potentially unlock new therapies.

Radiofrequency ablation: mechanisms and clinical applications

Radiofrequency ablation (RFA), a form of thermal ablation, employs localized heat to induce protein denaturation in tissue cells, resulting in cell death. It has emerged as a viable treatment option for patients who are ineligible for surgery in various diseases, particularly liver cancer and other tumor-related conditions. In addition to directly eliminating tumor cells, RFA also induces alterations in the infiltrating cells within the tumor microenvironment (TME), which can significantly impact treatment outcomes. Moreover, incomplete RFA (iRFA) may lead to tumor recurrence and metastasis. The current challenge is to enhance the efficacy of RFA by elucidating its underlying mechanisms. This review discusses the clinical applications of RFA in treating various diseases and the mechanisms that contribute to the survival and invasion of tumor cells following iRFA, including the roles of heat shock proteins, hypoxia, and autophagy. Additionally, we analyze‌ the changes occurring in infiltrating cells within the TME after iRFA. Finally, we provide a comprehensive summary of clinical trials involving RFA in conjunction with other treatment modalities in the field of cancer therapy, aiming to offer novel insights and references for improving the effectiveness of RFA.

Potential Cost Savings with 60-day Peripheral Nerve Stimulation Treatment in Chronic Axial Low Back Pain

INTRODUCTION

Chronic axial low back pain (CLBP) that is not responsive to medication management or physical therapy often requires significant clinical intervention. Several interventional pain management options exist, including a 60-day peripheral nerve stimulation (PNS) treatment. This economic evaluation investigated the potential for projected cost savings associated with prioritizing 60-day PNS treatment relative to a 'standard of care' (SOC) approach (where patients do not have access to 60-day PNS).

METHODS

A decision tree (supervised machine learning) model tracked treatment progression across two hypothetical cohorts of US patients with CLBP in whom non-interventional options were ineffective (Cohort A: treatment starting with 60-day PNS followed by any additional interventional and surgical treatments versus Cohort B: standard of care interventional and surgical treatments without access to 60-day PNS). Treatment efficacy estimates were based on published success rates. Conditional on treatment failure, up to two additional interventions were considered within the 12-month time frame in both cohorts. SOC treatment options included epidural injection, radiofrequency ablation (RFA), basivertebral nerve ablation (BVNA), PNS permanent implant (PNS-PI), spinal cord stimulator (SCS) trial/implant, and spinal fusion surgery. Treatment choice probabilities in both cohort algorithms were based on clinician interviews. Costs were based on national Medicare reimbursement levels in the ambulatory surgery center (ASC) setting. Savings reflected the difference in projected costs between cohorts. A Monte Carlo simulation and sensitivity analyses were conducted to generate confidence intervals and identify important inputs.

RESULTS

The treatment algorithm which prioritized initial 60-day PNS treatment was projected to save $8056 (95% CI $6112-$9981) per patient during the first year of interventional treatment relative to the SOC approach.

CONCLUSIONS

Use of the 60-day PNS treatment as an initial interventional treatment in patients with CLBP may result in significant savings for Medicare. Projected savings may be even larger for commercial payers covering non-Medicare patients.

Radiofrequency Denervation of the Spine and the Sacroiliac Joint: A Systematic Review based on the Grades of Recommendations, Assesment, Development, and Evaluation Approach Resulting in a German National Guideline

STUDY DESIGN

Systematic review of the literature and subsequent meta-analysis for the development of a new guideline.

OBJECTIVES

This manuscript summarizes the recommendations from a new clinical guideline published by the German Spine Society. It covers the current evidence on recommendations regarding the indication, test blocks and use of radiofrequency denervation. The guidelines aim is to improve patient care and efficiency of the procedure.

METHODS

A multidisciplinary working group formulated recommendations based on the Grades of Recommendations, Assessment, Development, and Evaluation (GRADE) approach and the Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument.

RESULTS

20 clinical questions were defined for guideline development, with 87.5% consensus achieved by committee members for one recommendation and 100% consensus for all other topics. Specific questions that were addressed included clinical history, examination and imaging, conservative treatment before injections, diagnostic blocks, the injected medications, the cut-off value in pain-reduction for a diagnostic block as well as the number of blocks, image guidance, the cannula trajectories, the lesion size, stimulation, repeat radiofrequency denervation, sedation, cessation or continuation of anticoagulants, the influence of metal hardware, and ways to mitigate complications.

CONCLUSION

Radiofrequency (RF) denervation of the spine and the SI joint may provide benefit to well-selected individuals. The recommendations of this guideline are based on very low to moderate quality of evidence as well as professional consensus. The guideline working groups recommend that research efforts in relation to all aspects of management of facet joint pain and SI joint pain should be intensified.

Optimal caudal needle angulation for lumbar medial branch denervation: A 3D cadaveric and clinical imaging comparison study

Background

Lumbar medial branch (MB) radiofrequency ablation is a common intervention to treat facetogenic low back pain. The consensus among spine pain interventionalists is that capturing a greater length of the MB correlates with a longer duration of pain relief. Therefore, there has been interest in defining optimal needle angles to achieve parallel cannula placement. Presently, there is inconsistency regarding the optimal caudal needle angles.

Objectives

The objectives of this study were to: 1) use a dissection-based 3D modelling methodology to quantify optimal caudal needle angles from cadaveric models; and 2) compare optimal cadaver-derived caudal needle angles with real-world patient-derived needle angles.

Methods

Eighteen formalin embalmed lumbosacral spine specimens were dissected, digitized, and modelled in 3D. Virtual needles were simulated and placed parallel with the L1-L5 MBs. Cadaver-derived caudal needle angles were measured from the high-fidelity 3D models with optimally placed virtual needles. Lateral fluoroscopic images of patients (n = 200) that received lumbar MB denervation were reviewed to measure patient-derived caudal needle angles (L3-L5 MB levels). Descriptive statistics were used to analyze the cadaver (L1-L5 MB levels) and patient-derived (L3-L5 MB levels) caudal needle angles. The cadaver and patient-derived mean caudal needle angles for L3-L5 MB levels were compared.

Results

There was variability in the cadaver-derived mean caudal needle angles. The lowest mean caudal needle angle was the L1 MB level measured at 41.57 ± 8.56° (range: 27.14° - 53.96°). The highest was the L5 MB level with a mean caudal needle angle of 60.79 ± 8.55° (range: 46.97° - 79.74°). A total of 123 patients were included and 369 caudal needle angles (L3-L5 MB levels) were measured and analyzed. There was variability in the patient-derived mean caudal needle angles. The patient-derived mean caudal needle angles were 29.18 ± 8.77° (range: 11.80° - 61.31°), 33.34 ± 7.23° (range: 16.40° - 54.15°), and 49.08 ± 8.87° (range: 26.45° - 76.95°) for the L3, L4, and L5 MB levels, respectively. There was a significant difference in mean caudal needle angle between cadaver and patient-derived needle angles at the L3, L4, and L5 MB levels.

Conclusions

Analysis of cadaver-derived needle angles versus patient-derived data suggests optimization of lumbar MB denervation requires greater caudal angulation to achieve parallel needle placement. Further research is required to assess the clinical implications.

Osteoarthritis of zygapophysial joints as a cause of back pain and neck pain: a scoping review

BACKGROUND

Zygapophysial joints (Z joints) can be a source of back pain and of neck pain, but the cause of pain is not known. Some authors attribute the pain to osteoarthritis but without citing evidence.

OBJECTIVES

The present review was undertaken to determine if there was sufficient evidence of association between spinal pain and osteoarthritis of Z joints to justify osteoarthritis being held to be the cause of pain. The null hypothesis was that osteoarthritis of Z joints does not cause back pain or neck pain.

ELIGIBILITY CRITERIA

Relevant studies were ones that provided primary data on the association between pain and osteoarthritis of Z joints. These could be population studies, diagnostic studies, or case-control studies.

SOURCES OF EVIDENCE

The database of PubMed was searched using the terms: Lumbar or cervical, zygapophysial or facet, pain, and osteoarthritis or degeneration or degenerative.

CHARTING METHODS

Data pertinent to the research question were extracted from original articles and tabulated for reporting. Odds ratios for associations were calculated, as were the prevalence rates of osteoarthritis in subjects with pain, and conversely the prevalence rates of pain in subjects with osteoarthritis.

RESULTS

The searches retrieved 11 population studies, 4 diagnostic studies, and 3 cases control studies. No study showed any positive association between osteoarthritis of Z joints and pain. All studies found pain to be independent of the presence or severity of osteoarthritis. Osteoarthritis was as common in subjects with no pain as in subjects with pain. The null hypothesis was not refuted.

CONCLUSION

The published evidence does not support the belief that osteoarthritis causes Z joint pain. All the evidence contradicts this belief.

Exploring the Therapeutic Potential of Mesenchymal Stem Cells-derived conditioned medium: An In-depth Analysis of Pain Alleviation, Spinal CCL2 Levels, and Oxidative Stress

Neuropathic pain, a debilitating condition, remains a significant challenge due to the lack of effective therapeutic solutions. This study aimed to evaluate the potential of mesenchymal stromal cell (MSC)-derived conditioned medium in alleviating neuropathic pain induced by sciatic nerve compression injury in adult male rats. Forty Wistar rats were randomly assigned to four groups: control, nerve injury, nerve injury with intra-neural injection of conditioned medium, and nerve injury with intra-neural injection of culture medium. Following sciatic nerve compression, the respective groups received either 10 µl of conditioned medium from amniotic fluid-derived stem cells or an equal volume of control culture medium. Behavioral tests for cold allodynia, mechanical allodynia, and thermal hyperalgesia were conducted, and the spinal cord was analyzed using Western Blot and oxidative stress assays. The behavioral experiments showed a decrease in mechanical hyperalgesia and cold allodynia in the group receiving conditioned medium compared to the injury group and the control medium group. Western blot data revealed a decrease in the expression of the CCL2 protein and an increase in GAD65. Oxidative stress tests also showed increased levels of SOD and glutathione in conditioned media-treated animals compared to animals with nerve injury. The findings suggest that conditioned medium derived from amniotic fluid-derived stem cells can effectively reduce neuropathic pain, potentially through the provision of supportive factors that mitigate oxidative stress and inflammation in the spinal cord.

Chronic Low Back Pain: History, Symptoms, Pain Mechanisms, and Treatment

Chronic low back pain (cLBP) is the most frequently reported cause of years lived with disability. Identifying the anatomical structures or dysfunction contributing to patients' symptoms is critical to guiding treatment. The etiology of back pain and differential diagnosis is often broad, ranging from non-degenerative cLBP (trauma, tumor, inflammation, infection, etc.) to degenerative (also described as nonspecific) cLBP. After eliminating suspicion for more insidious causes of cLBP, a thorough investigation can be conducted in an attempt to identify a source of degenerative cLBP. Degenerative cLBP can originate from many sources, and a detailed understanding of the structures potentially involved is invaluable for an accurate diagnosis. This review article aims to provide a broad overview of the utility of clinical history, physical exam findings, imaging findings, and diagnostic procedures in identifying the cause of patients' cLBP. We provide a framework to help guide clinicians by dividing the structures into groups as follows: anterior vertebral column, posterior vertebral column, and extra-vertebral pain. For each condition listed, we touch on the treatment options that can be considered.

True lateral imaging during lumbar medial branch radiofrequency neurotomy: Interobserver reliability

Background

True lateral imaging (TLI), obtained by superimposing bilateral lumbar spine structures and aligning superior endplate cortical bone, requires deliberate rotational adjustments of the laterally positioned fluoroscope in both the axial and longitudinal planes. True lateral segmental imaging is necessary to depict true and accurate radiofrequency (RF) cannula positioning relative to bony anatomy during lumbar medial branch radiofrequency neurotomy (LMBRFN).

Objective

To determine the interobserver reliability of TLI during LMBRFN.

Methods

This was a retrospective review of a prospectively generated collection of lateral fluoroscopic images to determine the interobserver reliability of TLI during LMBRFN. Lateral fluoroscopic images were prospectively collected from 34 consecutive L4-5 and L5-S1 LMBRFN procedures during routine clinical practice. Employing International Pain and Spine Intervention Society (IPSIS) LMBRFN and TLI techniques, an RF cannula was positioned parallel to the L3 and L4 medial branches and the L5 dorsal rami. During the normal course of TLI, untrue and final true lateral segmental images were obtained and saved. An original data set of 100 pairs of true and untrue lateral images was reviewed to verify true laterality using established criteria; disagreement was resolved by consensus or discarding ambiguous cases. To measure interobserver reliability (Cohen's Kappa), two blinded expert reviewers independently reviewed the image set, identifying the true lateral image and the plane requiring correction.

Results

The observers agreed upon 98/98 true lateral RF-segment images (Kappa score 1.0 [1.00,1.00]). The observers agreed upon 86/98 maneuvers to correct the untrue RF-segment image. The Kappa score for determining the most appropriate corrective maneuver was 0.76 (0.63,0.89), showing substantial interobserver agreement.

Conclusions

The true lateral image of the targeted RF segment during LMBRFN was reliably determined with perfect interobserver agreement. Interobserver agreement was substantial regarding the maneuver to achieve TLI.

3D nerve proximity mapping of the medial branch of lumbar dorsal ramus: An anatomical study

Objective

Lumbar medial branch (MB) radiofrequency ablation is a common intervention to treat facetogenic low back pain. Consensus among spine pain interventionalists is that the cannula tip should be placed adjacent to the periosteum of the lateral neck of the superior articular process (SAP) to ensure maximum contact with the MB. The spatial relationship of the nerve to the periosteum of the lateral neck of the SAP has not been quantified in 3D. The objectives of the current study were to: 1) use 3D modelling technology to quantify the location along the lateral neck of the SAP where the MB is in direct contact with the periosteum; and 2) identify target site(s) to optimize lumbar MB denervation.

Design

Seventy lumbar dorsal rami in 14 formalin-embalmed specimens were dissected, digitized, and modeled in 3D. The 3D positional data of the MB were used to generate a novel nerve proximity map which provided a method to quantify and visualize the 3D course of the MB in relation to the periosteum of the lateral neck of SAP. The percent of the lateral neck of SAP in contact with the MB was quantified and consistent target site(s) identified.

Results

There was variability in the percentage of the lateral neck of SAP in contact with the MB. The mean percentage of the lateral neck of SAP in contact with the MB for the L1-L5 levels ranged between 57.39 ± 10.72 % (for L1) to 81.54 ± 10.48 % (for L5). The nerve proximity map showed consistent course of the MB along the posterior portion of the lateral neck of SAP and at a novel target site distal to the mamillo-accessory notch (i.e. sub-mammillary landmark).

Conclusion

The percent of the lateral neck that was in contact with the MB was quantified and visualized using a novel nerve proximity mapping methodology which may be used to inform cannula tip depth placement. Further, the nerve proximity maps were used to identify an alternative landmark to extend the length of the MB captured. The proposed sub-mammillary landmark may be a viable target site pending future anatomical and clinical investigations.

High-fidelity 3D modelling of the lumbar dorsal rami

Objective

Lumbar medial branch denervation is commonly used to treat chronic facetogenic low back pain. Controversy exists regarding risk to adjacent neural structures. The objectives of this cadaveric study were to: (1) dissect, digitize, and model in 3D the branches of the first (L1) to fifth (L5) lumbar dorsal rami located near the junction of the transverse process and lateral neck of the superior articular process; and (2) quantify the minimal distance between the lateral/intermediate and medial branches at the anterior quarter and midpoint of the lateral neck of the superior articular process.

Design

Eighteen formalin-embalmed specimens were dissected, digitized and modeled in 3D. The high-fidelity 3D models were used to compare branching patterns and quantify the mean minimal distance between the lateral/intermediate and medial branches of the lumbar dorsal ramus at the anterior quarter and midpoint of the lateral neck of the superior articular process. A Two-way ANOVA was performed to determine if difference of mean distances was significant.

Results

There was variability in the branching pattern of the lumbar dorsal rami. In 46 cases (51.1%) the lumbar dorsal ramus divided into 2 branches, in 41 cases (45.6%) into 3, and in 3 cases (3.3%) 4. The mean minimal distance between the lateral/intermediate and medial branches was significantly greater at the midpoint (3.2 ± 2.5 mm) than the anterior quarter (1.2 ± 1.8 mm) of the lateral neck of superior articular process.

Conclusion

Minimal distance measurements between the branches of the lumbar dorsal rami at the anterior quarter and midpoint of the lateral neck of the superior articular process were computed. When placing the distal end of the needle tip at the anterior quarter of the lateral neck of the superior articular process, the smaller mean minimal distance between the branches suggests there is a greater risk for inadvertent denervation of the lateral/intermediate branches. Further anatomical and clinical investigations are required.

[Evidence-based interventions to treat chronic low back pain: treatment selection for a personalized medicine approach : German version]

INTRODUCTION

Chronic low back pain (cLBP) is highly prevalent in the United States and globally, resulting in functional impairment and lowered quality of life. While many treatments are available for cLBP, clinicians have little information about which specific treatment(s) will work best for individual patients or subgroups of patients. The Back Pain Research Consortium, part of the National Institutes of Health Helping to End Addiction Long-termSM (HEAL) Initiative, will conduct a collaborative clinical trial, which seeks to develop a personalized medicine algorithm to optimize patient and provider treatment selection for patients with cLBP.

OBJECTIVE

The primary objective of this article is to provide an update on evidence-based cLBP interventions and describe the process of reviewing and selecting interventions for inclusion in the clinical trial.

METHODS

A working group of cLBP experts reviewed and selected interventions for inclusion in the clinical trial. The primary evaluation measures were strength of evidence and magnitude of treatment effect. When available in the literature, duration of effect, onset time, carryover effect, multimodal efficacy, responder subgroups, and evidence for the mechanism of treatment effect or biomarkers were considered.

CONCLUSION

The working group selected 4 leading, evidence-based treatments for cLBP to be tested in the clinical trial and for use in routine clinical treatment. These treatments include (1) duloxetine, (2) acceptance and commitment therapy, (3) a classification-based exercise and manual therapy intervention, and (4) a self-management approach. These interventions each had a moderate to high level of evidence to support a therapeutic effect and were from different therapeutic classes.

Quantification of needle angles for lumbar medial branch denervation targeting the posterior half of the superior articular process: an osteological study

BACKGROUND

Lumbar medial branch radiofrequency ablation (RFA) is a common intervention to manage chronic axial low back pain originating from the facet joints. A more parasagittal approach targeting the posterior half of the lateral neck of superior articular process (SAP) was previously proposed. However, specific needle angles to achieve parallel placement at this target site have not been investigated.

OBJECTIVE

To quantify and compare the needle angles, on posterior and lateral views, to achieve parallel placement of electrodes along the medial branch at the posterior half of the lateral neck of SAP at each lumbar vertebral level (L1-L5) and sacrum.

DESIGN

Osteological Study.

METHODS

Twelve disarticulated lumbosacral spines (n = 72 individual bones) were used in this study. Needles were placed along the periosteum of the posterior half of the lateral neck of SAP, bilaterally and photographed. Mean needle angles for each vertebral level (L1-L5) and sacrum were quantified, and statistical differences were analyzed.

RESULTS

The posterior view provided the degrees of lateral displacement from the parasagittal plane (abduction angle), while the lateral view provided the degrees of declination (cranial-to-caudal angle) of the needle. Mean needle angles at each level varied, ranging from 5.63 ± 5.76° to 14.50 ± 14.24° (abduction angle, posterior view) and 40.17 ± 7.32° to 64.10 ± 9.73° (cranial-to-caudal angle, lateral view). In posterior view, a < 10-degree needle angle interval was most frequently identified (57.0% of needle placements). In lateral view, the 40-50-degree (L1-L2), 50-60-degree (L3-L5), and 60-70-degree (sacrum) needle angle intervals occurred most frequently (54.2%, 50.0%, and 41.7% of needle placements, respectively).

CONCLUSIONS

Targeting the posterior half of the lateral neck of SAP required <10-degree angulation from parasagittal plane in majority of cases. However, variability of needle angles suggests a standard "one-size-fits-all" approach may not be the optimal technique.

A pragmatic randomized prospective trial of cooled radiofrequency ablation of the medial branch nerves versus facet joint injection of corticosteroid for the treatment of lumbar facet syndrome: 12 month outcomes

BACKGROUND

Lumbar medial branch radiofrequency ablation (LRFA) and intraarticular facet steroid injections (FJI) are commonly performed for recalcitrant facet joint-mediated pain. However, no study has compared clinical outcomes of the two treatments in patients selected using dual medial branch blocks (MBBs) with an 80% relief threshold.

OBJECTIVE

Compare the effectiveness of cooled LRFA (C-LRFA) to FIJ as assessed by pain and functional improvements.

DESIGN

Prospective randomized comparative trial.

METHODS

Patients with dual MBB-confirmed facet joint-mediated pain were randomized to receive C-LRFA or FIJ. Outcomes were assessed at 1, 3, 6, and 12 months. The primary outcome was ≥50% improvement in numerical pain rating scale (NPRS) score at 3 months. Secondary outcomes included ≥30% Oswestry Disability Index (ODI) improvement and Patient Global Impression of Chance (PGIC) ≥6 points, among others. Data were analyzed using contingency tables and mixed-effects logistic regression models.

RESULTS

Of 1128 patients screened, 32 met eligibility criteria, were randomized, and received their allocated study treatment. In total, 20 (62.5%) and 12 (37.5%) participants received C-LRFA and FIJ, respectively. In the C-LRFA group, 70% (95% CI 48-85), 55% (95% CI 34-74), and 45% (95% CI 26-66) of participants met the NPRS responder definition, compared to 25% (95%CI 9-53), 25% (95% CI 9-53), and 17% (95% CI 5-45) in the FJI group at 3, 6, and 12 months, respectively (P = .014 at 3 months). The PGIC responder proportion was higher in the C-LRFA compared to FJI group at 3 and 6 months (P < .05).

CONCLUSIONS

C-LRFA demonstrated superior success rates compared to FJI across pain and functional outcome domains.

TRIAL REGISTRATION DETAILS

ClinicalTrials.gov (NCT03614793); August 3, 2018.

Can ultrasound-guided radiofrequency ablation of genicular nerves of the knee, be performed without locating corresponding arterial pulsations-a cadaveric study

INTRODUCTION

Given the rising prevalence of knee osteoarthritis, radiofrequency ablation of genicular nerves (RFA) has emerged as a promising treatment option for knee pain. The knee has an extremely complex and variable innervation with nearly 13 genicular nerves described. The frequently ablated genicular nerves are the superomedial (SMGN), the superolateral (SLGN), and the inferomedial (IMGN) genicular nerves. Conventionally, under ultrasound guidance, these nerves are ablated near the corresponding arterial pulsations, but due to the rich vascular anastomosis around the knee joint, identifying the arteries corresponding to these constant genicular nerves can be tedious unless guided by some bony landmarks. In this study, we have evaluated whether it is possible to accurately target these three genicular nerves by just locating bony landmarks under ultrasound in human cadaveric knee specimens.

METHODS

Fifteen formalin-fixed cadaveric knee specimens were studied. SMGN was targeted 1 cm anterior to the adductor tubercle in the axial view. For SLGN, in the coronal view, the junction of the lateral femoral condyle and shaft was identified, and at the same level in the axial view, the crest between the lateral and posterior femoral cortex was targeted. For IMGN in the coronal view, the midpoint between the most prominent part of the medial tibial condyle and the insertion of the deep fibers of the medial collateral ligament was marked. The medial end of the medial tibial cortex was then targeted at the same level in the axial view. The needle was inserted from anterior to posterior, with an in-plane approach for all nerves. Eosin, 2% W/V, in 0.1 ml was injected. Microdissection was done while keeping the needle in situ. Staining of the nerve was considered a positive outcome, and the percentage was calculated. The nerve-to-needle distance was measured, and the mean with an interquartile range was calculated.

RESULT

The accuracies of ultrasound-guided bony landmarks of SMGN, SLGN, and IMGN were 100% in terms of staining, with average nerve-to-needle distances of 1.67, 3.2, and 1.8 mm respectively.

CONCLUSION

It is with 100% accuracy, that we can perform RFA of SMGN, SLGN, and IMGN under ultrasound guidance, by locating the aforementioned bony landmarks.

Quantification of Needle Angles for Traditional Lumbar Medial Branch Radiofrequency Ablation: An Osteological Study

BACKGROUND

Clinical outcomes following lumbar medial branch radiofrequency ablation (RFA) have been inconsistent. One possible reason is less-than-optimal placement of the electrode along the medial branch at the lateral neck of superior articular process (SAP). Needle angles that define optimal placement (i.e., parallel to the medial branch) may be helpful for consistent technical performance of RFA. Despite its importance, there is a lack of anatomical studies that quantify RFA needle placement angles.

OBJECTIVE

To quantify and compare needle angles to achieve parallel placement along the medial branch as it courses on the middle two-quarters of the lateral neck of the SAP at the L1-L5 vertebrae.

DESIGN

Osteological Study.

METHODS

Ten lumbar vertebral columns were used in this study. Needles were placed along the periosteum of the middle two-quarters of the lateral neck of SAP. Mean needle angles for L1-L5 were quantified and compared using posterior (n = 100) and lateral (n = 100) photographs.

RESULTS

Mean needle angles varied ranging from 29.29 ± 17.82° to 47.22 ± 16.27° lateral to the parasagittal plane (posterior view) and 33.53 ± 10.23° to 49.19 ± 10.69° caudal to the superior vertebral endplate (lateral view). Significant differences in mean angles were found between: L1/L3 (P = .008), L1/L4 (P = .003), and L1/L5 (P = .040) in the posterior view and L1/L3 (P = .042), L1/L4 (P < .001), L1/L5 (P < .001), L2/L4 (P = .004), and L2/L5 (P = .004) in lateral view.

CONCLUSIONS

Variability of needle angles suggest a standard "one-size-fits-all" approach may not be the optimal technique. Future research is necessary to determine optimal patient-specific needle angles from a more detailed and granular analysis of fluoroscopic landmarks.

FactFinders for patient safety: Motor stimulation testing in lumbar radiofrequency neurotomy and radiofrequency neurotomy in patients with posterior hardware

This series of FactFinders presents a brief summary of the evidence and outlines recommendations regarding the use of motor stimulation testing in lumbar radiofrequency neurotomy and performance of radiofrequency neurotomy in patients with posterior spinal hardware. The evidence in support of the following facts is presented: (1) Motor stimulation does not inherently protect against unwanted damage to the spinal nerve, exiting spinal nerve root or its ventral ramus due to a lack of sensitivity of this test for identification of electrode contact or close proximity to sensorimotor nerves. Even when motor stimulation is performed, verification of correct electrode placement with multiplanar imaging including a minimum of true anterior-posterior and lateral fluoroscopic views is a recommended safeguard. (2) The existence of posterior spinal hardware is not an absolute contraindication to radiofrequency neurotomy, but direct contact with hardware should be avoided.

Radiofrequency Ablation for Chronic Lumbar Zygapophyseal Joint Pain Using a V-Shaped Active Tip Needle: An Observational Retrospective Study

Background

Lumbar zygapophyseal joint dysfunction represents one of the major sources of chronic low back pain. Radiofrequency ablation (RFA) using a V-shaped active tip needle may offer a larger lesion of the medial branch nerves, improving clinical outcome. The aim of our study is to evaluate the efficacy and the feasibility of RFA using V-shaped active tip needles.

Methods

This is a single-center observational retrospective study. Clinical records were screened and analyzed if they met the following inclusion criteria: adult patients (>18 years), diagnosis of chronic lumbar zygapophyseal joint pain, failure of conservative treatments, ability to provide informed consent for data analysis and publication. Exclusion criteria: lumbar pain not related to zygapophyseal joints, previous spinal/lumbar surgery, incomplete data, absence or withdrawal of informed consent. The primary outcome of the study was a change in pain intensity at follow-up. The secondary outcomes were the evaluation of quality-of-life improvement, the occurrence of adverse events and the impact on post-procedural analgesic consumption. For these purposes, pre- and post-treatment numeric rating scale (NRS), neuropathic pain 4 questions (DN4), EuroQoL - EQ-5D-3L, EQ-VAS, EQ-index and North American Spine Society (NASS) index were retrieved and analysed.

Results

Sixty-four patients were included. 7.8% of patients at 1-month (CI95% 0.026, 0.173), 37.5% at 3-month (CI95% 0.257, 0.505), 40.6% at 6-month (CI95% 0.285, 0.536) and 35.9% at 9-month (CI95% 0.243, 0.489) follow-up reported a reduction of more than 80% in NRS Statistical analysis indicated a significant change in NRS, DN4, EQ-index and EQ-5D-VAS (p-value <0.001) at the different time-points.

Conclusion

RFA using a V-shaped active tip needle might be a feasible and effective treatment for chronic lumbar zygapophyseal joint pain.

The Role of Hypertonic Saline in Ablative Radiofrequency of the Sacroiliac Joint: Observational Study of 40 Patients

BACKGROUND

The aim of this retrospective uncontrolled article is to illustrate a technique of neurotomy of the sensitive branches of S1 S2 S3 in RFA that appears to result in a better success rate and longer-lasting pain relief.

METHODS

40 patients were treated, 26 females and 14 males, with an average age of 74 (92-55). After the examination, the patients underwent an ultrasound-guided diagnostic block of the affected sacroiliac joint. Only patients who presented pain relief greater than 60% after the diagnostic block were candidates for the RFA procedure. The procedure was always performed in the operating room on an outpatient basis. After obtaining the best fluoroscopic visualization of the joint to be treated, two RFA cannulae were placed starting from the lower medial margin parallel to the SIJ to perform a bipolar RFA along the entire medial margin of the SIJ. Lidocaine 2% and hypertonic saline 2 mEq/mL were used for each RFA level. Patients were followed-up at 3, 6, 12, 18, and 24 months by evaluating the NRS and SF-12.

RESULTS

Patients reported extreme satisfaction with the procedure performed and reported a significant improvement in NRS and SF-12 at FU visits. No adverse events occurred.

CONCLUSIONS

Bipolar RFA treatment of the sacroiliac joint with the use of a hypertonic saline solution appears to improve the success of the method and its durability. We are inclined to believe that the use of hypertonic saline may significantly increase the lesion area and result in a greater effect on the sensory branches.

Facet Joint Syndrome: Pathophysiology, Diagnosis, and Treatment

Facet joint osteoarthritis (OA) is the most frequent form of facet joint syndrome. Medical history, referred pain patterns, physical examination, and diagnostic imaging studies (standard radiographs, magnetic resonance imaging, computed tomography and single-photon emission computed tomography) may suggest but not confirm lumbar facet joint (LFJ) syndrome as a source of low back pain (LBP). However, the diagnosis and treatment of facet joint syndrome is still controversial and needs further study. It is widely acknowledged that block with local anesthetic is perhaps the most effective method to establish a diagnosis of pain from LFJ. Particularly, there are different rates of success among different populations selected for diagnostic block with various positive criteria. Currently, in addition to conservative treatments for pain such as painkillers, functional exercises, and massage, there are many other methods, including block, denervation of the nerves that innervate the joints by radiofrequency, freezing or endoscopy, and injections. Due to the limited duration of pain relief from neurolysis of medial branch, many scholars have recently turned their targets to dorsal roots and LFJ capsules. Therefore, we reviewed the latest research progress of facet joint syndrome from diagnosis to treatment.

Comparison of Endoscopic Facet Joint Denervation to the Percutaneous Technique Regarding Efficacy in Patients With Low Back Pain: A Randomized Controlled Trial

STUDY DESIGN

This was a single-center prospective randomized controlled study.

OBJECTIVE

The aim was to compare the efficacy of endoscopic facet joint denervation (FJD) with that of the percutaneous technique in terms of pain, functional disability, and quality of life in patients with low back pain (LBP).

SUMMARY OF BACKGROUND DATA

Different controlled studies in patients with LBP have shown short-term benefits from percutaneous FJD. Observational studies have demonstrated that endoscopic FJD may be more effective. As the superiority of the endoscopic technique has not been clearly demonstrated in previous studies, a prospective randomized controlled study was conducted.

MATERIALS AND METHODS

For this study, 40 patients with LBP lasting more than 6 months duration and at least 50% pain reduction on the visual analog scale after medial branch block under fluoroscopy, were assigned randomly to receive percutaneous or endoscopic FJD. The primary outcome was pain, as indicated by visual analog scale. Secondary outcomes were functional disability, as assessed by the Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (RDQ), and quality of life, as assessed by the Short Form Health Survey (SF-36).

RESULTS

After the intervention, the pain level decreased significantly in both groups ( P <0.001); however, the effect was still significant in the endoscopic group (EG) and diminished to lower than the statistical significance in the percutaneous group (PG) after 12 months. The ODI and RDQ scores also improved significantly in both groups ( P <0.001). However, the ODI and RDQ were significantly better ( P <0.001) in the EG after 12 months. In the SF-36, we observed significant improvement in both groups three months after the intervention. The effect decreased after six months in the PG and was predominantly not demonstrable after 12 months, whereas in the EG there was still a strong significant improvement on all scales ( P <0.001) after 12 months.

CONCLUSION

Percutaneous and endoscopic FJD reduced pain and improved functionality and quality of life. However, the effects decreased or disappeared in the PG after 12 months, whereas there was still a strong significant improvement in the EG.

Evidence-based interventions to treat chronic low back pain: treatment selection for a personalized medicine approach

Literature on current treatments for chronic low back pain (cLBP) were reviewed and 4 interventions were recommended for inclusion in a multisite cLBP clinical trial.

Introduction:

Objective:

Methods:

Conclusion:

Effect of radiofrequency denervation on pain severity among patients with cervical, thoracic or lumbar spinal pain: A clinical retrospective study

Background

Low back pain is the leading cause of job-related disabilities. The zygapophyseal (facet) joint has been identified as a cause of spinal pain in 15%–45% of individuals. Radiofrequency ablation (RFA) to the facet joints of the lumbar, cervical and thoracic regions and discussion of the 2-year follow-up results will provide additional data and contribute to understanding the long-term effectiveness of RFA.

Methods

Patients with cervical, thoracic or low back pain, not accompanied by radicular pain and without primary and/or metastatic disease in the spinal region during radiological evaluation were retrospectively analysed. A total of 1274 patients aged >18 years who had clinical follow-up for at least 1 year and had back pain for >6 months were included in the study. The RFA groups were compared within themselves before and after the application. Moreover, patients who received RFA were compared with those who did not receive RFA (controls). The visual analogue scale and quality-of-life scores of the patients were evaluated. Periodic clinical follow-ups revealed changes in neurological status.

Results

Of the 774 patients who underwent RFA, 156, 184 and 434 patients had pain in the cervical, thoracic and lumbar and lumbosacral regions, respectively. The control groups consisted of 108, 122 and 270 patients, respectively. No significant difference in any of the baseline demographic variables was observed between the groups (p > 0.05). A significant improvement was found in both visual analogue scale and quality-of-life scores when compared before and after RFA application within the groups. In addition, a significant improvement was found in the RFA group compared with the control group.

Conclusions

As far as we know, this is the first comparative study of RFA involving the cervical, thoracic and lumbar spinal regions. RFA made it possible to obtain satisfactory results in all three regions. With its increasing popularity and frequency of use, new indications for RFA may emerge.

•

Radiofrequency ablation (RFA) method emerges as a very successful treatment method in patients who do not have an operative pathology but who suffer from chronic pain.

•

Especially, considering the persistent outpatient clinic admissions of patients with persistent low back pain, RFA is a "rescuer" position for most clinicians.

•

The clinical relief of the patients for two years is one of the most critical data clearly demonstrating the long-term success of the procedure.

Patient-perceived duration of effect of lidocaine and bupivacaine following diagnostic medial branch blocks; a multicenter study

Objective

To quantify the duration of pain relief reported in association with lidocaine and bupivacaine in patients suffering from axial back pain, who reported a response of ≥80% relief lasting at least 30 ​min following medial branch blocks(MBB).

Design

A retrospective review.

Methods

Setting & Subjects: Four academic medical centers utilized a uniform pain diary. It was administered to consecutive patients after undergoing MBB. This pain diary included NRS pain score and percentage of pain relief (PPR) at 12 designated time points.

Results

One hundred and fifty pain diaries were collected and analyzed. 42 blocks were performed in the cervical spine, 7 in the thoracic spine, and 101 in the lumbar spine. By NRS, 32% of pain diaries indicated that the patient experienced ≥80% pain relief at the 30-min and 42.7% (64/150) did so by PPR. Mean duration of ≥80% pain relief as measured by NRS in the bupivacaine subgroup was 3.5 ​h (SD 8.7, 95% CI 0.6-6.5) versus mean duration of 16.4 ​h (SD 19.6, 95% CI 5.4-27.4) in the lidocaine subgroup. Mean duration of ≥80% pain relief as measured by PPR in the bupivacaine subgroup was 19.2 ​h (SD 19.2, 95% CI 13.3-25.1) versus mean duration of 12.2 ​h (SD 15.9, 95% CI 5.6-18.8) in the lidocaine subgroup.

Conclusions

This study demonstrates that there is no discernable or statistically significant difference in the duration of effect when comparing lidocaine to bupivacaine in patients that experience 80% or more relief following a medial branch block. This data suggests any emphasis on concordant duration of relief from specific anesthetics utilized for diagnostic medial branch blocks should be reconsidered.

Anatomical study of the medial branches of the lumbar dorsal rami: implications for image-guided intervention

INTRODUCTION

Fluoroscopic-guided radiofrequency ablation of the lumbar medial branches is commonly performed to manage chronic low back pain originating from the facet joints. A detailed understanding of the course of medial branches in relation to bony and soft tissue landmarks is paramount to optimizing lumbar denervation procedures, particularly parallel placement of the radiofrequency electrode. The objectives of this study were to investigate the relationship of medial branches to anatomical landmarks and discuss the implications for lumbar denervation.

METHODS

Ten cadaveric specimens were meticulously dissected. The origin, course, and relationship of lumbar medial branches to bony and soft tissue landmarks were documented.

RESULTS

The medial branches followed the lateral neck of superior articular process deep to the intertransversarii mediales muscle at each lumbar vertebral level. In all specimens, the medial branches coursed laterally on the anterior half of the neck and transitioned from parasagittal-to-medial on the posterior half to reach the mamillo-accessory notch. The mamillo-accessory ligament was found to not occlude the nerve on the posterior quarter of the lateral neck but rather at the mamillo-accessory notch located at the posterior margin of the superior articular process.

DISCUSSION

A detailed understanding of the relationship of medial branches to anatomical landmarks is essential to optimizing needle placement for lumbar denervation procedures. The current study suggests that a parasagittal placement, with increased cranial-to-caudal angulation of the electrode, may improve parallel tip alignment with the targeted medial branch and represent a potential alternative to the traditional technique.

Lumbar medial branch block progression to radiofrequency neurotomy: A retrospective audit of clinical practice

Introduction

Chronic axial low back pain due to zygapophysial joint arthropathy is best diagnosed via lumbar medial branch block (MBB). However, the paradigm by which MBB is used to select patients for lumbar radiofrequency neurotomy (RFN) is contested. Dual diagnostic lumbar MBB with a minimum of ≥80% pain relief to diagnose lumbar zygapophysial joint pain are accepted by some Medicare Local Coverage Determination (LCD) as the method for selecting patients for RFN for the management of lumbar zygapophysial joint pain. However, some argue that dual diagnostic MBB and the ≥80% pain relief threshold lack utility in clinical practice, given that those that progress from MBB1 to MBB2 will then flow from MBB2 to RFN without fail.

Study

Pragmatic retrospective clinical audit.

Objective

Does clinical practice of dual diagnostic lumbar MBBs and an ≥80% pain improvement diagnostic threshold reduce patient eligibility for RFN after both MBB1 and MBB2?

Results

Using dual diagnostic lumbar MBBs and an ≥80% pain improvement diagnostic threshold, 90/167 (54%, 95% CI 46-61%) patients successfully progressed from MBB1 to MBB2. Of those 90 patients, 66 patients (73%, 95% CI 64-82%) successfully progressed from MBB2 to RFN. Both MBB1 and MBB2 impacted the eligibility of the progression of 77/167 (46%, 95% CI 39-54%) patients and 24/90 patients (27%, 95% CI 18-36%), respectively. An additional sub-cohort analysis which included all the patients from the ≥80% pain relief cohort, and those who progressed at the discretion of the providers with 50-79% relief revealed that 124/167 patients (74%, 95% CI 68-81%) successfully progressed from MBB1 to MBB2. Of those 124 patients, 99 patients (80%, 95% CI 73-87%) progressed from MBB2 to RFN. In this laxer criteria cohort, MBB1 and MBB2 impacted the eligibility of the progression of 43/167 patients (26%, 95% CI 19-32%) and 25/124 patients (20%, 95% CI 13-27%), respectively.

Conclusion

MBB1 and MBB2 both filtered patients from progression to lumbar RFN using dual MBBs with an ≥80% pain relief criteria. It also held true when using a more relaxed pain relief selection criterion as well. Dual MBB's and ≥80% pain improvement criteria as a selection paradigm led to half as many lumbar RFNs being performed when compared to a single MBB and ≥80% pain improvement criteria. In theory, a more rigid selection paradigm treats less patients but exposes fewer to unnecessary RFNs while a laxer selection paradigm treats more patients but exposes more to unnecessary RFNs.

Characterizing an angle of cannula insertion for Lumbar Medial Branch Radiofrequency Neurotomy: A retrospective observational study

Objective

Evidence characterizing a starting angle of radiofrequency (RF) cannula insertion during radiofrequency neurotomy is lacking. Using computerized tomography (CT), this retrospective observational study attempts to establish a starting angle for RF cannula placement parallel to the transverse process (TP) at the junction of the superior articular process (SAP) near the targeted medial branch.

Methods

This retrospective observational study utilized lumbar spine CT scans performed on adult cancer patients from January 2016 to May 2021 ​at a single center. No significant lumbar pathology was present on the included CT studies. For each patient, medial branches were assumed to lie at the junction of the right and left TP and SAP at each lumbar level. The angle of insertion from each segment's "squared" superior end plate needed for RF cannula placement parallel to the surface of the TP next to the SAP was calculated.

Results

Images obtained from fifty patients were analyzed. Mean angle of insertion for L1 was 20.15 ​± ​1.82°, L2 was 20.95 ​± ​2.07°, L3 was 25.54 ​± ​1.76°, L4 was 31.01 ​± ​1.83°, and L5 was 40.74 ​± ​1.86°.

Conclusion

This study demonstrates variations in inserting angle for RF cannula placement parallel to the surface of the transverse process at each lumbar level. To our knowledge, there are no studies in the current literature that have described an entry angle for RF cannula positioning parallel to lumbar medial branches using CT images.

What does the patient with back pain want? A comparison of patient preferences and physician assumptions

BACKGROUD CONTEXT

Low back pain can be difficult to diagnose, leaving patients frustrated and confused after medical visits.

PURPOSE

To evaluate the importance of reasons for seeking care in patients with back pain, and to compare this to physicians' assumptions about these patients' reasons.

STUDY DESIGN/SETTING

Prospective survey study carried out at two academic spine centers.

PATIENT SAMPLE

A sum of 419 patients with back pain upon initial presentation to a spine clinic, and 198 physicians; all volunteered to complete a survey.

OUTCOME MEASURES

Variance in mean values between patient and physician responders with significance determined by non-overlapping 95% confidence intervals.

METHODS

Patients were asked to "rate each of the following with regard to their importance to you" (answering between 0 "not important" to 4 "extremely important"): improvement in level of pain, improvement in ability to perform daily tasks, explanation of what is causing your problem, thorough physical examination, diagnostic testing, medication, physical therapy, surgery. Physicians were asked to rate each of these "with regard to their importance to your patients."

RESULTS

Patients indicated the following items were the most important (mean values): explanation of what is causing your problem (3.27), improvement in level of pain (3.48) and improvement in ability to perform daily tasks (3.31). Patients attributed the least importance and lowest scores to: surgery (1.07) and medication (1.89). Comparing the mean values to each item by patient and physician responders revealed statistically significant differences in certain items. Specifically, physicians underestimated the importance of an explanation of what is causing the problem (2.78±0.119 vs. 3.28±0.098, 95% CI) and overvalued diagnostic tests (2.64±0.120 vs. 2.30±0.147, 95% CI), medications (2.38±0.118 vs. 1.89± 0.143, 95% CI) and surgery (1.60±0.126 vs. 1.07±0.140, 95% CI).

CONCLUSION

Patients did not place as much importance on diagnostic tests, medications and surgery as the physicians assumed. Physicians understand that back pain patients want improvement in both pain and function, but they underestimate the importance of an explanation for the pain.

Evaluation of an Ultrasound-Assisted Longitudinal Axis Lateral Crest Approach to Radiofrequency Ablation of the Sacroiliac Joint

OBJECTIVE

The aim of the study was to evaluate the effectiveness and procedural characteristics of a novel, ultrasound/fluoroscopically guided technique (longitudinal axis sacroiliac joint radiofrequency ablation) for sacroiliac joint denervation.

DESIGN

A single-arm cohort with historical cohort comparison was used in this study.

METHODS

Thirty-seven participants underwent longitudinal axis sacroiliac joint radiofrequency ablation after 50% or more pain reduction after diagnostic dual-block criterion. Outcomes were the proportion of participants with 50% or more pain reduction and mean Pain Disability Quality of Life Questionnaire change. Subanalysis included longitudinal axis sacroiliac joint radiofrequency ablation procedural and fluoroscopy times compared with participants previously treated with palisade radiofrequency ablation technique.

RESULTS

Primary outcome worst case analysis demonstrated a responder rate of 64.9% (95% confidence interval = 48.8%-78.2%) and 59.5% (95% confidence interval = 43.5%-73.7%) at 3 and 6 mos. There was significant decrease in mean Pain Disability Quality of Life Questionnaire at 3 (45.6 ± 9.5 to 21.4 ± 16.0, P < 0.001) and 6 mos (45.6 ± 9.5 to 23.0 ± 16.5, P < 0.001). Longitudinal axis sacroiliac joint radiofrequency ablation required more procedure time than the palisade technique (38.2 ± 7.9 vs. 32.1 ± 6.9 mins, P = 0.031) but less fluoroscopy time (35.0 ± 11.8 vs. 57.6 ± 16.8 secs, P < 0.001).

CONCLUSIONS

Longitudinal axis sacroiliac joint radiofrequency ablation resulted in improvement in pain, disability, and quality of life at 3 and 6 mos. Compared with the palisade technique, longitudinal axis sacroiliac joint radiofrequency ablation required greater procedure time but less fluoroscopy time.

The Role of Diagnostic Injections in Spinal Disorders: A Narrative Review

Neck and back pain is increasingly prevalent, and has increased exponentially in recent years. As more resources are dedicated to the diagnosis of pain conditions, it is increasingly important that the diagnostic techniques used are as precise and accurate as possible. Traditional diagnostic methods rely heavily upon patient history and physical examination to determine the most appropriate treatments and/or imaging studies. Though traditional means of diagnosis remain a necessity, in many cases, correlation with positive or negative responses to injections may further enhance diagnostic specificity, and improve outcomes by preventing unnecessary treatments or surgeries. This narrative review aims to present the most recent literature describing the diagnostic validity of precision injections, as well as their impact on surgical planning and outcomes. Diagnostic injections are discussed in terms of facet arthropathy, lumbar radiculopathy, discogenic pain and discography, and sacroiliac joint dysfunction. There is a growing body of evidence supporting the use of diagnostic local anesthetic injections or nerve blocks to aid in diagnosis. Spinal injections add valuable objective information that can potentially improve diagnostic precision, guide treatment strategies, and aid in patient selection for invasive surgical interventions.